Semiconductor device packaging fulfills basic functions such as providing electrical connections and protecting the semiconductor die against mechanical and environmental stresses. Continued progress in reduction of the size of the semiconductor dies and increased functionality and complexity of the circuits integrated in the semiconductor dies also require size reduction of the packaging with the same or greater complexity of the electrical connections with external circuits.
Semiconductor devices are commonly packaged for surface mounting by encapsulating one or more semiconductor dies with a mold compound. Electrical contacts for connection with external circuits are exposed at an exterior surface of the semiconductor package and are connected internally with electrical contact pads on the semiconductor die. Various techniques are available for connecting the exposed electrical contacts of the semiconductor package internally with the embedded semiconductor die.
One technique for connecting the exposed electrical contacts with the electrical contact pads on the semiconductor die entails temporarily placing singulated semiconductor dies with their active face on a substrate. The dies are embedded with a molding compound into a panel and then released from the substrate. The contact pads on the semiconductor die surfaces are then connected to exposed pads on the exterior surface of the package panel by a redistribution process to route out the signal connections, and the power and ground connections. The redistribution process includes deposition of a plurality of electrically conductive layers by electroplating techniques and patterning using batch process lithography. The electrically conductive layers are separated by insulating layers. Such a packaging technique can support high density interconnect routing, can minimize package area by reducing the distance between die contact and package ball grid array or pads, can improve power efficiency, and so forth.
Semiconductor dies can generate significant heat during operation. Semiconductor device packaging of some semiconductor dies has been problematic because the molding compound that encapsulates a semiconductor die cannot effectively dissipate heat generated by the semiconductor die. This trapped heat can cause poor performance and/or failure of the semiconductor device. Heat buildup can be exacerbated in semiconductor packages having multiple electrically conductive layers separated by insulating layers, such as in an RCP semiconductor package, because heat dissipation is limited by the relatively long interconnect routing within the RCP interconnect layers and by the metal structure (e.g., metal thickness and width).